Compressor

ABSTRACT

The invention relates to a compressor ( 1 ) for gaseous and/or cryogenically liquefied media comprising a first compressor piston ( 6 ) and a second compressor piston ( 7 ), which are operatively connected to an eccentric shaft ( 2 ), wherein the second compressor piston ( 7 ) is arranged substantially opposite to the first compressor piston ( 6 ) relative to the eccentric shaft ( 2 ). To solve the object of providing such a compressor with a small space requirement and low construction costs, it is proposed according to the invention for the compressor ( 1 ) to be embodied as an oscillating piston-type compressor, wherein the first compressor piston ( 6 ) is arranged on an eccentric ring ( 4 ), which is effectively connected to the eccentric shaft ( 2 ) and wherein the second compressor piston ( 7 ) is fastened to a pivot lug ( 8 ), which is effectively connected to the eccentric ring ( 4 ).

The invention relates to a compressor for gaseous and/or cryogenically liquefied media comprising a first compressor piston and a second compressor piston, which are operatively connected to an eccentric shaft, wherein the second compressor piston is arranged substantially opposite to the first compressor piston relative to the eccentric shaft.

Such compressors comprising two compressor pistons being arranged opposite one another are used to compress gaseous media and/or cryogenically liquefied (cryogenic) media, for example nitrogen, natural gas or hydrogen. The compressor can hereby be designed as a two-stage compressor, wherein the first compressor piston forms the input stage and the second compressor piston forms the output stage.

In known generic compressors comprising two compressor pistons, the two compressor pistons are spaced apart in an axial manner and are in each case connected to the eccentric shaft by means of a piston rod, which is in each case supported on the eccentric shaft and on the compressor piston in an articulated manner. By means of the compressor pistons, which are spaced apart in an axial manner, the compressor encompasses a large space requirement in axial direction. The compressor pistons hereby perform a linear motion in the corresponding compressor cylinder. However, the connection of the compressor piston to the eccentric shaft by means of the piston rod leads to high lateral guide forces at the compressor piston. Said lateral guide forces lead to large wear of the sealing device, which is arranged on the compressor piston, whereby the compressor encompasses a large amount of maintenance and thus high construction costs. The lateral guide forces can be reduced by extending the piston rod, whereby, however, the compressor also requires a Large amount of space in radial direction.

The instant invention is based on the object of providing a compressor of the afore-mentioned species, which requires a small amount of space and low construction costs.

According to the invention this object is solved in that the compressor is embodied as an oscillating piston-type compressor, wherein the first compressor piston is arranged on an eccentric ring, which is effectively connected to the eccentric shaft and in that the second compressor piston is fastened to a pivot lug, which is effectively connected to the eccentric ring. Due to the design of the compressor as an oscillating piston-type compressor, wherein the second compressor piston is connected to a pivot lug, which is connected to the eccentric ring, which is effectively connected to the eccentric shaft, wherein the first compressor piston is fastened to the eccentric ring, it is possible to make the design of a compressor comprising two compressor pistons to be simple and to be space-saving in axial and radial direction. Due to the embodiment of the compressor as an oscillating piston-type compressor, the compressor also encompasses very low lateral guide forces due to the fact that piston rods are not being used, whereby the compressor encompasses a long service life with a small amount of maintenance and thus low construction costs.

According to a preferred embodiment of the invention, a fastening lug, to which the first compressor piston is fastened, is embodied on the eccentric ring, wherein the pivot lug of the second compressor piston is arranged on the eccentric ring in an articulated manner in the area of the fastening lug of the first compressor piston. This articulated arrangement of the pivot lug on the eccentric ring makes it possible for the pendular motion and thus for the deflection of the second compressor piston to be less than the pendular motion and thus the deflection of the first compressor piston, wherein the lateral guide forces of the second compressor piston can be further reduced.

Low construction costs can be attained when the pivot lug is embodied according to a preferred embodiment of the invention as a bow-shaped component, which encompasses a cross-plate, to which the second compressor piston is fastened and two substantially ring-shaped side parts, which are spaced apart from one another, wherein a receiving space for the eccentric ring is embodied between the side parts. As a result of this, it is possible to arrange the first compressor piston and the second compressor piston in one plane in a simple manner and to thus attain a small space requirement of the compressor in axial direction.

Advantageously, a receiving bore for a hinge pin is embodied on the side parts. An articulated connection of the pivot lug, which is embodied in a bow-shaped manner, to the eccentric ring can he attained in a simple manner by means of a hinge pin, which is arranged and fastened in the receiving bore of the side parts of the pivot lug.

Provided that a through hole for the hinge pin is embodied on the eccentric ring, the hinge pin can be arranged in the eccentric ring in a simple manner and with low construction costs.

Particular advantages result when the hinge pin is supported in the through hole of the eccentric ring by means of a bush. Using a bush, in particular a plain bearing bush, it is possible to attain an articulated bearing of the pivot lug on the eccentric ring with a long service life with a small amount of maintenance in a simple manner by means of the hinge pin, which is fastened in the pivot lug.

According to an advantageous embodiment of the invention, the compressor is embodied as a two-stage compressor, wherein the first compressor piston forms the input stage and the second compressor piston forms the output stage of the compressor. With a compressor according to the invention, which is an oscillating piston-type compressor comprising two compressor pistons, provision can be made for a two-stage compressor, which requires a small amount of space and low construction costs. In the input stage, the gaseous medium and/or the cryogenically liquefied media, which can have an input temperature of up to −250° C., can hereby be compressed to an intermediate pressure of, for example, 10-15 bar, wherein an operating pressure of, for example, up to 450 bar can be generated in the output stage as a function of the area ratio of the first and the second compressor piston and thus as a function of the stage pressure ratio.

Advantageously, the first compressor piston is arranged in a first compressor cylinder and the second compressor piston is arranged in a second compressor cylinder, wherein the output of the first compressor cylinder is connected to the input of the second compressor cylinder. Due to the arrangement of the compressor pistons as being substantially opposite, wherein the compressor pistons are arranged so as to be offset by 180° relative to the eccentric shaft in response to an arrangement of the compressor pistons as being opposite and thus operate in a phase-shifted manner, the output of the first compressor piston can be directly connected to the input of the second compressor piston, whereby a two-stage compressor can be attained with low production costs. Instead of an offset angle of 180° of the first compressor piston and of the second compressor piston, provision can be made for different offset angles to improve the relative strengths and the moment ratios.

Further advantages and details of the invention are defined in more detail by means of the exemplary embodiment, which is illustrated in the schematic figures.

FIG. 1 shows a compressor according to the invention in a perspective illustration,

FIG. 2 shows a detailed view of FIG. 1,

FIG. 3 shows a side view of FIG. 2 and

FIG. 4 shows a top view of FIG. 2.

The perspective view of a compressor 1 according to the invention as an oscillating piston-type compressor is illustrated in FIG. 1.

The compressor 1 is embodied as a two-stage compressor and encompasses a ring-shaped housing 15, in which a first compressor cylinder 16, which forms the input stage, and a second compressor cylinder 17, which forms the output stage, is fastened. A cylinder head 18, 19, which forms the input as well as the output of the compressor cylinders 16, 17, is arranged in each case on the compressor cylinders 16, 17. On the input side, the cylinder head 18 is connected to an input line 20 for the gaseous medium, which is to be compressed. At the output side, an intermediate line 21, which guides the medium, which is compressed to the intermediate pressure by the input stage and which is guided to the input of the cylinder head 19, is connected to the cylinder head 18. At the output side, the cylinder head 19 is connected to an output line 22 for the medium, which is compressed to the operating pressure. A connection 23 for a safety valve, for example a pressure control valve, is embodied in the intermediate line 21.

As is shown in FIGS. 2 to 4, the compressor 1 encompasses an eccentric shaft 2, which is operatively connected to a crankshaft 24 illustrated in FIG. 1, which is rotatably mounted about an axis of rotation D. An eccentric ring 4 is fastened to said eccentric shaft 2 by means of a rolling bearing 3.

A fastening lug 5 is embodied on the eccentric ring 4. A first compressor piston 6, which is arranged in the first compressor cylinder 16, is fastened to said fastening lug 5. As can be seen in FIG. 3, a threaded hole 5 a, for example, is embodied on the fastening lug 5 for this purpose, wherein the first compressor piston 6 is fastened in the fastening lug 5 by means of a screw connection. The first compressor piston 6 is provided with a groove-shaped recess 6 a, in which a sealing device can be arranged. In response to a rotation of the crankshaft 24, the first compressor piston 6, which is connected to the crankshaft 24 via the eccentric ring 4 and the eccentric shaft 2, performs a pendular motion in the compressor cylinder 16.

The compressor 1 encompasses a second compressor piston 7, which is arranged in the compressor cylinder 17 and which is arranged so as to be offset by 180° and thus so as to be located opposite to the first compressor piston 6 relative to the eccentric shaft 2 and thus relative to the crankshaft 24 in the illustrated exemplary embodiment.

As can be seen from FIGS. 2 to 4, the second compressor piston 7 is fastened to a pivot lug 8, on which the eccentric ring 4 is fastened in an articulated manner about a pivot axis S, which is arranged parallel to the axis of rotation D, in the area of the fastening lug 5 of the first compressor piston 6. The second compressor piston 7 is provided with at least one groove-shaped recess 7 a, in which a sealing device can be arranged.

The pivot lug 8 is embodied as a bow-shaped component comprising a cross-plate 8 a and side parts 8 b, 8 c, which are arranged on the cross-plate 8 a. The side parts 8 b, 8 c are hereby integrally molded on the cross-plate 8 a in one piece. The second compressor piston 7 is fastened to the cross-plate 8 a. For this purpose, a threaded hole 8 d, into which the second compressor piston 7 can be screwed, is embodied in the cross-plate 8 a, for example.

The side parts 8 b, 8 c are embodied in a substantially ring-shaped manner and are spaced apart from one another in axial direction of the axis of rotation D, whereby a receiving space for the eccentric ring 4 is formed between the side parts 8 b, 8 c. A receiving bore 10, which forms the pivot axis S, is embodied on the side parts 8 b, 8 c in the area located opposite to the cross-plate 8 a. Said receiving bore 10 is formed, for example, by a through hole in the side part 8 b and by a threaded hole in the side part 8 c. A hinge pin 11 is arranged and screwed into the receiving bore 10.

A through hole 12 is embodied on the eccentric ring 4 in the area of the fastening lug 5, by means of which the hinge pin 11 and thus the pivot lug 8 is connected to the eccentric ring 4. A bush 13, for example a plain bearing bush, can be arranged between the through hole 12 and the hinge pin 11.

Due to the articulated fastening of the pivot lug 8 of the second compressor piston 7, which is formed by the hinge pin 11, on the eccentric pin 4 in the area of the fastening lug 5 of the first compressor piston 6, an arrangement of the first compressor piston 6 so as to be located opposite relative to the axis of rotation D and of the second compressor piston 7 in a plane, which is perpendicular to the axis of rotation D, can be formed in a simple manner. This leads to a space-saving design of the compressor 1 according to the invention in axial direction. The embodiment of the compressor 1 as an oscillating piston-type compressor comprising two compressor pistons 6, 7, wherein a reduced pendular motion and a reduced deflection of the second compressor piston 7 is attained by pivoting the pivot lug 8, which is provided with the second compressor piston 7, to the fastening lug 5 of the first compressor piston 6, furthermore leads to a space-saving design of the compressor in radial direction, wherein, furthermore, very small lateral guide forces appear on the compressor pistons 6, 7 and the compressor according to the invention thus encompasses a small amount of maintenance and thus low construction costs. 

1. A compressor for gaseous and/or cryogenically liquefied media comprising a first compressor piston and a second compressor piston, which are operatively connected to an eccentric shaft, wherein the second compressor piston is arranged substantially opposite to the first compressor piston relative to the eccentric shaft, characterized in that the compressor is embodied as an oscillating piston-type compressor, wherein the first compressor piston is arranged on an eccentric ring, which is effectively connected to the eccentric shaft and wherein the second compressor piston is fastened to a pivot lug, which is effectively connected to the eccentric ring.
 2. The compressor according to claim 1, characterized in that a fastening lug, to which the first compressor piston is fastened, is embodied on the eccentric ring, wherein the pivot lug of the second compressor piston is arranged on the eccentric ring in an articulated manner in the area of the fastening lug of the first compressor piston.
 3. The compressor according to claim 1, characterized in that the pivot lug is embodied as a bow-shaped component, which encompasses a cross-plate, to which the second compressor piston is fastened and two substantially ring-shaped side parts, which are spaced apart from one another, wherein a receiving space for the eccentric ring is embodied between the side parts.
 4. The compressor according to claim 3, characterized in that a receiving bore for a pivot pin is embodied on the side parts.
 5. The compressor according to claim 4, characterized in that a through hole for the pivot pin is embodied on the eccentric ring.
 6. The compressor according to claim 5, characterized in that the pivot pin is supported in the through hole of the eccentric ring via a bush.
 7. The compressor according to claim 1, characterized in that the compressor is embodied as a two-stage compressor, wherein the first compressor piston forms the input stage and the second compressor piston forms the output stage of the compressor.
 8. The compressor according to claim 7, characterized in that the first compressor piston is arranged in a first compressor cylinder and the second compressor piston is arranged in a second compressor cylinder, wherein the output of the first compressor cylinder is connected to the input of the second compressor cylinder. 